Partial or total knee replacement?

The difference

A total knee replacement resurfaces the whole joint. A partial knee replacement replaces only the worn part, most often the inner (medial) side, and keeps the healthy rest of the knee and its ligaments.

Side by side

	Partial knee	Total knee
Who is suitable	Arthritis in one part of the knee, healthy ligaments, good movement	Most people with knee arthritis
Hospital stay	Usually 0 to 1 nights	Usually 1 to 2 nights
Recovery	Often quicker	Full recovery up to 12 months
Driving	Often after 4 to 6 weeks	Usually after about 6 weeks
How it feels	Often feels more like a natural knee	Most people are very satisfied
Serious complications in the first months	Less common	Uncommon
Lasting more than 15 years (implants I use)	91 in 100	95 in 100

What the research shows

• A large UK trial (TOPKAT) found that patients did as well after a partial as after a total knee replacement at five years.
• National Joint Registry studies and a review published in the BMJ found lower risks of complications, such as blood clots, heart attack, stroke and deep infection, after a partial knee replacement.
• Partial knee replacements are more likely to need further surgery later. If that happens, a partial knee can usually be converted to a total knee replacement.

National guidance (NICE) recommends that people with arthritis in the inner part of the knee are offered the choice of either operation.

How I help you decide

I will examine your knee and review standing X-rays, and sometimes further X-rays, to see whether a partial knee replacement is possible for you. Where both are suitable, we will weigh up the quicker recovery of a partial knee against the slightly higher chance of further surgery, in the light of your age, activity and preferences. Either operation can be done with Mako robotic assistance, but I use it only where it is appropriate for you.

Written and reviewed by Mr Krishna Boddu FRCS (Tr & Orth), consultant orthopaedic surgeon, GMC 5206961. Last reviewed: 3 November 2026.

Sources

• NICE guideline NG157: Joint replacement (primary): hip, knee and shoulder (2020)
• Beard DJ et al. The clinical and cost-effectiveness of total versus partial knee replacement in patients with medial compartment osteoarthritis (TOPKAT): 5-year outcomes of a randomised controlled trial. Lancet 2019;394:746–56.
• Wilson HA et al. Patient relevant outcomes of unicompartmental versus total knee replacement: systematic review and meta-analysis. BMJ 2019;364:l352.
• Liddle AD et al. Adverse outcomes after total and unicompartmental knee replacement in 101,330 matched patients: a study of data from the National Joint Registry for England and Wales. Lancet 2014;384:1437–45.
• National Joint Registry annual reports: implant survival
• Gill JR, Nicolai P. Clinical results and 12-year survivorship of the Physica ZUK unicompartmental knee replacement. Knee 2019;26:750–8.